Mutations of the CACNA1A gene, located on chromosome 19p13.13, coding for the α1 pore –forming subunit of the voltage-gated calcium channel P/Q type (Cav2.1), were identified as responsible for three autosomal dominant disorders with incomplete penetrance: FHM1, EA2, and spinocerebellar ataxia type 6 (SCA6, MIM:183086) [3, 4]. Here, CACNA1A is linked to spinocerebellar ataxia type 6.